A vibration generator has recently been used in a portable terminal, such as a cellular phone handset and a personal digital assistant (PDA), operation equipment, such as a controller for a game, and the like.
As the vibration generators for such a use, ones having the following configurations and operation are used, as also shown in Patent Documents 1 and 2.
That is, a vibration generator is made up of a first mover composed of a magnet supported by a plate spring and a yoke, and a stator composed of a coil fixed to a housing, or a second mover composed of a coil fixed on a vibrating plate in place of the stator.
Then, the first mover generates vibrations and the second mover generates sounds by the operation of magnetic force generated by the magnet and electromagnetic force generated by a current flowing through the coil.
This kind of vibration generator has conventionally adopted a system of resonating a vibration system, composed of a plate spring and a mover, by electrifying the coil with almost the same frequency as the resonance frequency of the vibration system (Patent Document 3). The frequency characteristic of a vibration generator is generally shown by an acute curve having a peak at a resonance frequency, and large vibration force can be obtained at the resonance frequency but the obtained vibration force becomes weaker as the input frequency deviates from the resonance frequency.
On the other hand, as described in Patent Documents 1 and 4, as the structure for fixing a plate spring to a housing (case), a structure of fixing the outer end portion of the plate spring by nipping the outer end portion with two parts of the case is sometimes adopted. Furthermore, in Patent Documents 1 and 4, the plate spring is fixed in such a way that the central part (inner circumferential part) thereof is superposed on the center of the yoke.
In recent years, devices on which vibration generators are installed have been miniaturized and thinned, and the vibration generators themselves have also been desired to be miniaturized and thinned.    Patent Document 1: Japanese Patent Publication No. 3375233    Patent Document 2: Japanese Patent Application Laid-Open Publication No. 2003-9495    Patent Document 3: Japanese Patent Application Laid-Open Publication No. H9-205763    Patent Document 4: Japanese Patent Application Laid-Open Publication No. H10-229596